Patents by Inventor Eugene A. Imhoff

Eugene A. Imhoff has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10403509
    Abstract: A method for removing existing basal plane dislocations (BPDs) from silicon carbide epilayers by using a pulsed rapid thermal annealing process where the BPDs in the epilayers were eliminated while preserving the epitaxial surface. This high temperature, high pressure method uses silicon carbide epitaxial layers with a carbon cap to protect the surface. These capped epilayers are subjected to a plurality of rapid heating and cooling cycles.
    Type: Grant
    Filed: April 6, 2015
    Date of Patent: September 3, 2019
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Marko J. Tadjer, Boris N. Feigelson, Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Jordan Greenlee
  • Patent number: 10343900
    Abstract: Material structures and methods for etching hexagonal, single-crystal silicon carbide (SiC) materials are provided, which include selection of on-axis or near on-axis hexagonal single-crystal SiC material as the material to be etched. The methods include etching of SiC bulk substrate material, etching of SiC material layers bonded to a silicon oxide layer, etching of suspended SiC material layers, and etching of a SiC material layer anodically bonded to a glass layer. Plasma-etched hexagonal single-crystal SiC materials of the invention may be used to form structures that include, but are not limited to, microelectromechanical beams, microelectromechanical membranes, microelectromechanical cantilevers, microelectromechanical bridges, and microelectromechanical field effect transistor devices.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: July 9, 2019
    Assignee: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Eugene A. Imhoff, Francis J. Kub, Karl D. Hobart, Rachael L. Myers-Ward
  • Patent number: 10317210
    Abstract: According to one aspect, embodiments herein provide a gyroscope comprising an axially symmetric structure, and a plurality of transducers, each configured to perform at least one of driving and sensing motion of the axially symmetric structure, wherein the plurality of transducers is configured to drive the axially symmetric structure in at least a first vibratory mode and a second vibratory mode, and wherein the gyroscope is implemented on a hexagonal crystal-based substrate.
    Type: Grant
    Filed: May 20, 2016
    Date of Patent: June 11, 2019
    Assignees: THE CHARLES STARK DRAPER LABORATORY, INC., The United States of America, as represented by the Secretary of the Navy
    Inventors: Francis J. Kub, Karl D. Hobart, Eugene Imhoff, Rachael Myers-Ward, Eugene H. Cook, Marc S. Weinberg, Jonathan J. Bernstein
  • Publication number: 20180244513
    Abstract: A structure and method of fabricating suspended beam silicon carbide MEMS structure with low capacitance and good thermal expansion match. A suspended material structure is attached to an anchor material structure that is direct wafer bonded to a substrate. The anchor material structure and the suspended material structure are formed from either a hexagonal single-crystal SiC material, and the anchor material structure is bonded to the substrate while the suspended material structure does not have to be attached to the substrate. The substrate may be a semi-insulating or insulating SiC substrate. The substrate may have an etched recess region on the substrate first surface to facilitate the formation of the movable suspended material structures. The substrate may have patterned electrical electrodes on the substrate first surface, within recesses etched into the substrate.
    Type: Application
    Filed: February 28, 2018
    Publication date: August 30, 2018
    Applicant: The Government of the United States of America, as represented by the Secretary of the Navy
    Inventors: Francis J. Kub, Karl D. Hobart, Eugene A. Imhoff, Rachael L. Myers-Ward
  • Patent number: 10020366
    Abstract: A method and device including adding a protective layer on the surface of a substrate, annealing the substrate at a temperature approximately greater or equal to 1850° C., removing the protective layer from the surface of the substrate after the annealing, and growing a first epilayer on the substrate after the removing of the protective layer, wherein the first epilayer is grown without attempting to prevent the basal plane dislocations to propagate in the first epilayer when growing the first epilayer, and wherein the first epilayer is free of the basal plane dislocations.
    Type: Grant
    Filed: September 22, 2016
    Date of Patent: July 10, 2018
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Marko J. Tadjer
  • Publication number: 20180086625
    Abstract: Electromechanical device structures are provided, as well as methods for forming them. The device structures incorporate at least a first and second substrate separated by an interface material layer, where the first substrate comprises an anchor material structure and at least one suspended material structure, optionally a spring material structure, and optionally an electrostatic sense electrode. The device structures may be formed by methods that include providing an interface material layer on one or both of the first and second substrates, bonding the interface materials to the opposing first or second substrate or to the other interface material layer, followed by forming the suspended material structure by etching.
    Type: Application
    Filed: September 7, 2017
    Publication date: March 29, 2018
    Applicants: The Government of the United States of America, as Represented by the Secretary of the Navy, The Charles Stark Draper Laboratory, Inc.
    Inventors: Francis J. KUB, Karl D. HOBART, Eugene A. IMHOFF, Rachael L. MYERS-WARD, Eugene COOK, Jonathan BERNSTEIN, Marc WEINBERG
  • Publication number: 20180065844
    Abstract: Material structures and methods for etching hexagonal, single-crystal silicon carbide (SiC) materials are provided, which include selection of on-axis or near on-axis hexagonal single-crystal SiC material as the material to be etched. The methods include etching of SiC bulk substrate material, etching of SiC material layers bonded to a silicon oxide layer, etching of suspended SiC material layers, and etching of a SiC material layer anodically bonded to a glass layer. Plasma-etched hexagonal single-crystal SiC materials of the invention may be used to form structures that include, but are not limited to, microelectromechanical beams, microelectromechanical membranes, microelectromechanical cantilevers, microelectromechanical bridges, and microelectromechanical field effect transistor devices.
    Type: Application
    Filed: September 7, 2017
    Publication date: March 8, 2018
    Applicant: The Government of the United States of America, as Represented by the Secretary of the Navy
    Inventors: Eugene A. IMHOFF, Francis J. KUB, Karl D. HOBART, Rachael L. MYERS-WARD
  • Publication number: 20170092724
    Abstract: A method and device including adding a protective layer on the surface of a substrate, annealing the substrate at a temperature approximately greater or equal to 1850° C., removing the protective layer from the surface of the substrate after the annealing, and growing a first epilayer on the substrate after the removing of the protective layer, wherein the first epilayer is grown without attempting to prevent the basal plane dislocations to propagate in the first epilayer when growing the first epilayer, and wherein the first epilayer is free of the basal plane dislocations.
    Type: Application
    Filed: September 22, 2016
    Publication date: March 30, 2017
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Marko J. Tadjer
  • Publication number: 20160341552
    Abstract: According to one aspect, embodiments herein provide a gyroscope comprising an axially symmetric structure, and a plurality of transducers, each configured to perform at least one of driving and sensing motion of the axially symmetric structure, wherein the plurality of transducers is configured to drive the axially symmetric structure in at least a first vibratory mode and a second vibratory mode, and wherein the gyroscope is implemented on a hexagonal crystal-based substrate.
    Type: Application
    Filed: May 20, 2016
    Publication date: November 24, 2016
    Inventors: Francis J. Kub, Karl D. Hobart, Eugene Imhoff, Rachael Myers-Ward, Eugene H. Cook, Marc S. Weinberg, Jonathan J. Bernstein
  • Publication number: 20150287613
    Abstract: A method for removing existing basal plane dislocations (BPDs) from silicon carbide epilayers by using a pulsed rapid thermal annealing process where the BPDs in the epilayers were eliminated while preserving the epitaxial surface. This high temperature, high pressure method uses silicon carbide epitaxial layers with a carbon cap to protect the surface. These capped epilayers are subjected to a plurality of rapid heating and cooling cycles.
    Type: Application
    Filed: April 6, 2015
    Publication date: October 8, 2015
    Inventors: Marko J. Tadjer, Boris N. Feigelson, Nadeemullah A. Mahadik, Robert E. Stahlbush, Eugene A. Imhoff, Jordan Greenlee
  • Patent number: 9129799
    Abstract: A method to remove basal plane dislocations in post growth silicon carbide epitaxial layers by capping post growth silicon carbide epilayers with a graphite cap and annealing the capped silicon carbon epilayers at a temperature of 1750° C. or greater with a nitrogen overpressure of 60-110 psi, wherein basal plane dislocations in the epilayers are removed while surface morphology is preserved. Also disclosed is the related silicon carbide substrate material made by this method.
    Type: Grant
    Filed: September 26, 2014
    Date of Patent: September 8, 2015
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Marko J. Tadjer, Eugene A. Imhoff, Boris N. Feigelson
  • Publication number: 20150155166
    Abstract: A method to remove basal plane dislocations in post growth silicon carbide epitaxial layers by capping post growth silicon carbide epilayers with a graphite cap and annealing the capped silicon carbon epilayers at a temperature of 1750° C. or greater with a nitrogen overpressure of 60-110 psi, wherein basal plane dislocations in the epilayers are removed while surface morphology is preserved. Also disclosed is the related silicon carbide substrate material made by this method.
    Type: Application
    Filed: September 26, 2014
    Publication date: June 4, 2015
    Inventors: Nadeemullah A. Mahadik, Robert E. Stahlbush, Marko J. Tadjer, Eugene A. Imhoff, Boris N. Feigelson
  • Publication number: 20150056763
    Abstract: A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.
    Type: Application
    Filed: August 20, 2014
    Publication date: February 26, 2015
    Inventors: Karl D. Hobart, Tatyana I. Feygelson, Eugene A. Imhoff, Travis J. Anderson, Joshua D. Caldwell, Andrew D. Koehler, Bradford B. Pate, Marko J. Tadjer, Randijer S. Sandhu, Vincent Gambin, Gregory Lewis, Ioulia Smorchkova, Mark Goorsky, Jeff McKay
  • Patent number: 8723218
    Abstract: Silicon carbide PiN diodes are presented with reduced temperature coefficient crossover points by limited p type contact area to limit hole injection in the n type drift layer in order to provide a lower current at which the diode shifts from negative temperature coefficient to a positive temperature coefficient of forward voltage for mitigating thermal runaway.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: May 13, 2014
    Assignee: The United States of America, as represented by the Secretary of the Navy
    Inventors: Karl D. Hobart, Francis J. Kub, Mario Ancona, Eugene A. Imhoff
  • Publication number: 20130240905
    Abstract: Silicon carbide PiN diodes are presented with reduced temperature coefficient crossover points by limited p type contact area to limit hole injection in the n type drift layer in order to provide a lower current at which the diode shifts from negative temperature coefficient to a positive temperature coefficient of forward voltage for mitigating thermal runaway.
    Type: Application
    Filed: September 6, 2012
    Publication date: September 19, 2013
    Inventors: Karl D. Hobart, Francis J. Kub, Mario Ancona, Eugene A. Imhoff
  • Patent number: 7759186
    Abstract: Methods for producing a junction termination extension surrounding the edge of a cathode or anode junction in a semiconductor substrate, where the junction termination extension has a controlled arbitrary lateral doping profile and a controlled arbitrary lateral width, are provided. A photosensitive material is illuminated through a photomask having a pattern of opaque and clear spaces therein, the photomask being separated from the photosensitive material so that the light diffuses before striking the photosensitive material. After processing, the photosensitive material so exposed produces a laterally tapered implant mask. Dopants are introduced into the semiconductor material and follow a shape of the laterally tapered implant mask to create a controlled arbitrary lateral doping profile and a controlled lateral width in the junction termination extension in the semiconductor.
    Type: Grant
    Filed: July 6, 2009
    Date of Patent: July 20, 2010
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Eugene A. Imhoff, Francis J. Kub, Karl D. Hobart
  • Publication number: 20100055882
    Abstract: Methods for producing a junction termination extension surrounding the edge of a cathode or anode junction in a semiconductor substrate, where the junction termination extension has a controlled arbitrary lateral doping profile and a controlled arbitrary lateral width, are provided. A photosensitive material is illuminated through a photomask having a pattern of opaque and clear spaces therein, the photomask being separated from the photosensitive material so that the light diffuses before striking the photosensitive material. After processing, the photosensitive material so exposed produces a laterally tapered implant mask. Dopants are introduced into the semiconductor material and follow a shape of the laterally tapered implant mask to create a controlled arbitrary lateral doping profile and a controlled lateral width in the junction termination extension in the semiconductor.
    Type: Application
    Filed: July 6, 2009
    Publication date: March 4, 2010
    Applicant: The Government of the United States of America, as rpresented by the Secretary of the Navy
    Inventors: Eugene A. Imhoff, Francis J. Kub, Karl D. Hobart
  • Patent number: 5981975
    Abstract: An optoelectronic apparatus has, a die having a mesa (103) with a surface emitting optical device and a metallized p-type contact (209), a planar pad (201) adjacent the mesa for Z-height registration with an optical bench, a first notch (206) having been provided by a first etch and having thereon a metallized n-type contact (208) that is coplanar with the p-type contact (209), a second notch having a side surface (204) having been provided by a second etch, the second notch to abut the optical bench along an x-axis, the first notch (206) extending to the second notch, and the die having side surfaces (207) to abut the optical bench along a y-axis, and the second notch extending to the side surfaces (207).
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: November 9, 1999
    Assignee: The Whitaker Corporation
    Inventor: Eugene A. Imhoff